Which of the following diseases has NOT been reduced or eliminated by vaccines?

Your answer:
smallpox
AIDS
polio
measles

A natural vaccination happens when

Your answer:
a doctor gives a person a measles vaccine.
a person becomes immune to chicken pox after contracting it.
a person catches a cold.
after contracting influenza once, a person can contract it again.

Viruses are carried within the fluids and tissues of the body. They are spread between people in different ways, including

Your answer:
contact with contaminated blood.
insects that transmit infected blood.
contact with contaminated saliva or mucus.
all of the above.

The immune system protects the body from disease. Because the AIDS virus weakens the immune system,

Your answer:
people with AIDS are more vulnerable to other diseases.
the AIDS virus is spread very easily.
people with AIDS are immune to all other diseases.
all of the above.

Before its extinction in 1978, for how long had humans been affected by smallpox?

Your answer:
60 years
400 years
1,000 years
over 3,000 years

Some types of viruses are spread between animals and humans. An example of this is

Your answer:
a dog infected with rabies can infect people by biting them.
all colds are spread from cats to people.
horses often spread chicken pox to children.
a deer infected with measles will infect anyone who walks near it.

What ability do viruses have that we are trying to turn to our own advantage?

Your answer:
the ability to target specific areas of the body
the ability to spread quickly
the ability to break into cells
the ability to mutate and evolve